How to frame walls on concrete foundation

I'm planning to build a room on a porch. The porch has a concrete floor and to the landscaping is uneven - one side is below grade. I've done some landscaping to ensure water flows away from the porch, but it's still below grade. What is the proper way to build a wood wall on concrete base? I have a brick house so I'll need to secure the framing to the side of the house. I'm thinking 2x6 pressure treated lumber. Do I drill holes into the concrete slab to secure the walls? I have an existing roof that I don't plan to alter. Any opinions are greatly appreciated. Thanks!

I did find sill plate gasket foam online. Sounds like that may be what I need between the wood and concrete.

Replies to This Discussion

First thing you need to do Brian is get your shovel and dig around your pad and see if you have a foundation a stander concrete pad is 3 ½ “ thick but where you what to put walls you need more it’s a loud thing so take look and see what you got the old man always said if you got 6” to 8” you’ll be good to go let me now.

Sill plate gasket foam is for air sealing the sill plate, which assume that you will condition (heat or cool) the space inside. Are you planning to convert the open porch into a 3 or 4 season room?

Concrete is like a "hard sponge." since there is moisture in the dirt below the concrete, the moisture will migrate to the top surface of the concrete. You also have to protect the wood from rain splashing on the siding

2x6 or 2x4 PT is good. I like to drill holes thru the sill plate into the concrete and use concrete wedge fasteners like Red Head at Home Depot.

First thing you need to do Brian is get your shovel and dig around your pad and see if you have a foundation a stander concrete pad is 3 ½ “ thick but where you what to put walls you need more it’s a loud thing so take look and see what you got the old man always said if you got 6” to 8” you’ll be good to go let me now.

Thanks for the reply Rick. I'd like to make a functional room, maybe an office. I've seen Tapcom screws at HD not the Red Heads. I'll have to take a closer look later.

Rick said:

Sill plate gasket foam is for air sealing the sill plate, which assume that you will condition (heat or cool) the space inside. Are you planning to convert the open porch into a 3 or 4 season room?

Concrete is like a "hard sponge." since there is moisture in the dirt below the concrete, the moisture will migrate to the top surface of the concrete. You also have to protect the wood from rain splashing on the siding

2x6 or 2x4 PT is good. I like to drill holes thru the sill plate into the concrete and use concrete wedge fasteners like Red Head at Home Depot.

Well now that we know we have a foundation you need to do your home work on what kinds of cocking is out there and a good cocking gun . How you need to thank it over if you what to use anchor’s or theses blue masonry screws I forgot the name of them but they are being used more now days than anchor’s .

How with this in hand you well need to run you a bead down the edge of your concrete and than place you wall on top of that and then put you anchor’s or masonry screws in now this what they call old school you a roll of 12” flashing you need run it 6 for 6 first you need to run a bead on the side of your floor plate and a bead on the side of the concrete and than put your flashing 6’’ up on the wall and the other 6” down the side of concrete and watch the nails around the flashing.

Brian, noticed you are in Springfield -- I used to have family in Morton nearby.

Tapcons would work too, but usually with PL adhesive. Anchors are stronger if you use foam to seal.

Since you might make an office, generally having an insulated wood floor in an improvement. One solution is to build an insulated PT wood floor, which provides a level floor even with the house floor. It's more work, but it is warmer, flatter, and nicer for an office. Then the walls are built just like a house.

Brian said:

Thanks for the reply Rick. I'd like to make a functional room, maybe an office. I've seen Tapcom screws at HD not the Red Heads. I'll have to take a closer look later.

Well Ken and Rick has a piont the flashing thing only work for keeping the dirt and moisture out nothing stops water when it starts riseing. Thanks for jumping in guys back in the day we didnt have pressure treated lumber and yes I did get good with a star bit and hammer.

I would suggest using 1/2" Simpson TITEN HD anchor bolts (with square washer plates) to fasten the plates to the concrete. Drill 1/2 " holes in the concrete using an SD hammer drill. (Actually, drill the holes in the plates first, put them down on the concrete, and then drill the holes into the concrete.) The TITEN anchor bolts screw into the concrete holes and are more secure than expansion bolts.

Be sure to blow all of the concrete dust out of the holes before using either TITEN or expansion bolts. I used a piece of 1/4" tubing and compressed air. Place the suction of your shop vac hose over the hole when you do it, or you will have a lot of concrete dust in the air.